1. Field
Devices consistent with the present embodiment relate to an image forming apparatus capable of duplex printing, and more particularly, to a duplex-printable image forming apparatus which is capable of increasing a speed of duplex printing.
2. Description of the Related Art
In recent business environments, image forming apparatuses with duplex printability have been basically employed for protection of the environment and conservation of resources, and users and purchasers are demanding a small-sized image forming apparatus equipped with optimal printing capabilities, as well as all basic functionalities. To keep pace with this, efforts have been increasingly made to minimize a space within image forming apparatuses without deteriorating their performance.
In conventional image forming apparatuses with duplex printability, for simplex printing, a printing medium is fed from a feeding unit to a developing unit on which a visible image composed of a developer is formed. Thereafter, the printing medium is carried to a fixing unit by which the visible image is fixed onto the printing medium. The printing medium onto which the image has been fixed is discharged through a discharging roller adjacent to a discharging port, thereby allowing a user to obtain a print on which a desired image has been formed.
In the conventional image forming apparatuses with duplex printability, for duplex printing, the printing medium with its front side printed is partially discharged to a discharging unit and then reenters the image forming apparatus when the discharging roller is reversely rotated. The reentered printing medium enters a duplex printing path, is guided to the feeding unit, and then enters a developing roller. Then, a duplex printing is performed as a developer is applied on the rear side of the entered printing medium.
In the conventional image forming apparatuses with duplex printability, when the duplex printing is performed for a plurality of printing media, after duplex printing for a first printing medium is completed, a following second printing medium is duplex-printed.
Instead of the above method, in order to increase duplex printing efficiency, for an image forming apparatus with a sufficiently large size, a method of printing a front side of a second printing medium before printing a rear side of a first printing medium after printing a front side of the first printing medium is currently being used. Specifically, in this method, a conveying path through which printing media pass is formed to be sufficiently long, and the second printing medium is fed from a feeder and passes through a developing unit and a fixing unit while the first printing medium is being conveyed along a duplex printing path for rear side printing after the front side of the first printing medium is printed.
However, although this method may increase printing efficiency, the size of the image forming apparatus may increase since the conveying path has to be sufficiently secured such that the first printing medium does not overlap the second printing medium.
In addition, if the first and second printing media reside in the same path, the printing media are likely to be jammed.